The present invention relates generally to the field of anodes. Specifically, the present invention relates to the field of anodes for use on submersible motors, propellers and the like.
Certain materials (typically metals, and metal alloys) corrode (i.e. rust, pit, deteriorate, etc.) due to various corrosive phenomena. Such corrosive phenomena may include electrochemical corrosion such as galvanic corrosion. Galvanic corrosion occurs when dissimilar materials are in contact with each other, and an electrical circuit is completed. Often, electrolytic solutions complete the electrical connection which causes galvanic corrosion. Electrolytic solutions, which provide mobile charge carriers for the conduction of electrical current, are often provided by water, such as salt water, pond water, or other such solutions.
When dissimilar metals are in contact with each other in a xe2x80x9cgalvanic series,xe2x80x9d the more anodic material (i.e. the material with a higher tendency to sacrifice electrons in a galvanic series) will preferentially sacrifice electrons for the less anodic (or more cathodic) material. The electrons which are sacrificed for the cathodic material result in the corrosion or deterioration of the anodic material. Higher carrier mobility in the electrolytic solution may result in an enhanced or accelerated corrosion rate of the anodic material. Anodic materials may corrode at an enhanced or accelerated rate when submerged in electrolytic solutions such as water, including salt water, fresh water, etc.
It is know to provide an additional sacrificial anode, with higher anodic characteristics than the dissimilar materials which are to be protected, in electrical communication with the dissimilar materials, in order to inhibit or slow the rate of corrosion of the dissimilar materials. However, such sacrificial anodes are not well suited for use on submersible motors, propellers, lower units, and the like. Submersible motors, propellers, and lower units are often constructed from dissimilar materials, and submersed in an electrolytic solution such as pond water, lake water, salt water, etc. Due to this combination, the motors, propellers, and lower units may have an enhanced or accelerated rate of corrosion. Such arrangements often require the use of sacrificial anodes to slow or prevent corrosion.
However, typical sacrificial anodes often require multiple assembly steps to install the anode in the desired location. Furthermore, typical sacrificial anodes are not integral to the motor, propeller or lower unit, and may be difficult to install. Also, installing sacrificial anodes often requires compromising the body with invasive procedures such as drilling, tapping, etc.
Accordingly, it would be advantageous to provide an anode which would be integral to the design of the motor, propeller, or lower unit. It would also be advantageous to provide an anode with a design which minimizes the number of parts required, and reduces the cost of construction. Also, it would be advantageous to provide an anode which could be provided on a motor, propeller, or lower unit without additional assembly steps. It would further be advantageous to provide an anode which is easy to remove and replace. Furthermore, it would be advantageous to provide an anode which may be mounted without compromising the unit or body. It would also be advantageous to provide an anode which offers an integral construction.
It would be desirable to provide a propeller assembly which provides one or more of these advantageous features. The techniques below extend to those embodiments which fall within the scope of the appended claims, regardless of whether they provide one or more of the above-mentioned advantageous features.
According to one exemplary embodiment, a propeller attachment includes a body, the body including an anodic material, at least one projection projecting from the body, and a fastener coupled to the body.
According to another exemplary embodiment, an anode includes an annular body constructed from an anodic material, a fastener disposed centrally in the annular body, and at least one extension coupled to the annular body, the at least one extension is configured to allow for gripping of the anode.
According to another exemplary embodiment, a fastener for coupling a propeller to a drive shaft of a lower unit includes a fastening portion configured to threadably engage the drive shaft and retain the propeller. The fastener further includes an anodic portion disposed around the fastening portion. The anodic portion is shaped to form at least one grip, and the anodic portion preferentially corrodes to prevent corrosion of the lower unit.